"What I told them was they need to be prepared for the rest of the story,” Parrish said.

Parrish said every major hospital trains for mass casualty events, but he wanted medical staff in Las Vegas to know what he felt his team wasn't quite ready for.

"The patient identification process. The family reunification process,” Parrish said.

He said the damage caused by higher velocity firearms doesn't compare to a typical gunshot wound.

"I have no doubt those injuries were more severe than they might otherwise see,” Parrish said.

Parrish said the experience sticks with him and likely always will. He knows Las Vegas doctors and nurses will understand that soon, too. He just hopes sharing his story helped them cope a little better with their own.

"I tell them, I hope it never happens again. But the reason they're interested in having some of our staff there is because we all have a sense that it's very likely this may happen again,” Parrish said.